The roof structure of most conventional industrial buildings typically include rafters, purlins mounted on the rafters, and sheets of hard metal roofing material are mounted over the purlins. Blankets of insulation material typically are rolled out over the purlins, sandwiched between the purlins and the sheets of hard metal roofing material. Examples of such insulated roof structures are disclosed in U.S. Pat. Nos. 3,559,914, 4,047,345 and 4,147,003.
It has been proposed to combine sheets of radiant barrier materials, such as metal foils, between the blankets of insulation and the hard metal roofing material for retarding heat transfer through roof structures. A problem with such radiant barrier materials is that they are difficult and expensive to uniformly install, increasing the costs of insulating the roof structure. To provide an effective barrier against heat transfer, an air space or cavity in which the radiant barrier is positioned also is needed to enable the foil to reflect heat and retard its passage through the roof. If the upper blanket is in direct contact with the foil, the foil will tend to conduct, instead of reflect, heat through the roof and into the building.
Such air spaces generally have had to be formed by hand during the installation of the insulation blankets and reflective barrier materials, increasing installation costs. Additionally, the air spaces are typically formed above the blanket insulation material, and are exposed from above. As a result, dust can collect on the radiant barrier material, making it less reflective, which tends to diminish its effectiveness for retarding heat transfer.
Accordingly, it can be seen that it would be desirable to provide an apparatus and method of installing insulation material and a radiant barrier material into a roof structure for an industrial building that is easier and more economical to use to form an insulated roof structure having improved insulation and heat transfer retardant characteristics.